The Concept of Hierarchical Structure of Large Marine Ecosystems in the Zoning
4.6 Discussion
Landscape-bionomic concept characteristic of the Barents Sea as of the large marine system marked in scheme of ecoregions of Spalding et al. (2007) shown in Fig. 4.5 under # 18 was elaborated. Its structural elements became reason to discuss. The concept is based on the WWWF’s Arctic Programme (Barents Sea …. 2003) visual- ized on a map in Fig. 4.6. The map was taken as a basis issue where ecoregions shown in Fig. 4.6, are correlated with features deriving from joint analysis of distri- butions of principal geomorphological elements and macrobenthos shown in Figs. 4.7 and 4.8 respectively. A brief description of these ecoregions is provided below.
1. Southwestern ecoregion in Fig. 4.6 (1 a, Norway near-shore areas, and 1b, the Kola Peninsula near-shore areas) corresponds to Southwestern geomorphologi- cal area in Fig. 4.7. The coastline with narrow shelf is washed by waters of the North Atlantic current. The boreal fauna with relic forms in deep fjords prevails.
Owing to the influence of warm Atlantic water, coastal sites have the greatest variety of benthos presented with brown and red algae, sessile and vagile sesto- nophagous – filtrators on a stony slope. The variety and productivity of benthos decreases with depth.
2. Ecoregion of the Pechora Sea in Fig. 4.6 corresponds to Kanin-Pechora flat geo- morphological area in Fig. 4.7. In shallow waters on sandy-mud grounds sessile and vagile organisms prevail: sestonophagous, detritivores and ground feeders inhabiting the seabed. The dominating communities are bivalve molluscs Ciliatocardium ciliatum, Macoma calcarea and Serripes groenlandicus.
3. Ecoregion of the Central basin south from the polar front in Fig. 4.6 corresponds to the southern part of the Central Barents rift in and the West Barents Sea tec- tonic and geomorphological areas in Fig. 4.7 and represents a wide transition zone between the Atlantic and Arctic waters. Deep-water communities of ground
Fig. 4.5 Ecoregions of Euro-Asian shelf of Arctic realm modified from Spalding et al. (2007).
Fragment. 18 – North and East Barents Sea ecoregion
feeders polychaeta and sipunculida (Golfingia sp., Spiochaetopterus typicus, Ctenodiscus crispatus) as well as the community of holothurian (Trochostoma sp.) are characteristic. The Eastern part of this ecoregion coincides with the Central Lowland geomorphological area inhabited by boreal-arctic and arctic fauna of detritivores. Community of bivalve molluscs can be observed of family Astartidae (Elliptica elliptica and Astarte crenata), and deep-water community of polychaeta, sipunculida and holothurian can be found.
4. Ecoregion of the Central basin north from the polar front in Fig. 4.6 is situated in sphere of spreading of Arctic water masses. It occupies the northern part of the Central Barents Sea rift and belongs to the North Barents Sea geomorphological area in Fig. 4.7. This is a zone of detritivores collecting detritus from a seabed.
The deep-water community includes Ophiopleura borealis and foraminifer Hormosina globulifera, and also the community of bivalve molluscs of family Astartidae (Elliptica elliptica and Astarte crenata).
5. Ecoregion of the Novaya Zemlya shore in Fig. 4.6 corresponds to the Novaya Zemlya tectonic and geomorphological areas in Fig. 4.7. It is washed by the Arctic water mass with some influence of Atlantic water in the west. On sandy- mud bottom grounds the trophic groups comprise sessile and vagile sestonophagous- filtrators Hyatella arctica, Strongуlocentrotus sp., whereas Ophiura robusta, Balanus balanus are dominating in bentic community.
Fig. 4.6 Ecoregions of the Barents Sea: – South-Western (1a near-shore areas of Norway, and 1b the Kola Peninsula near-shore areas), 2 Pechora Sea, 3 Central basin south from the polar front, 4 Central basin north from the polar front, 5 Novaya Zemlya shore, 6 Svalbard Archipelago and banks of Spitsbergen, 7 Franz Josef Land Archipelago (Modified from Barents Sea Ecoregion 2003)
6. Ecoregion of the Svalbard Archipelago and the in banks of Spitsbergen in Fig. 4.6 is located inside the Spitsbergen highland geomorphological area in Fig. 4.7 filled by Arctic water mass but influenced by the North Atlantic. It is character- ized by high biodiversity. Trophic groups include macrophytobenthos, sessile and vagile sestonophagous-filtrators. On stony bottom grounds, the community of brown algae dominates. The community of sessile sestonophagous is formed
Fig. 4.7 Geomorphologic regionalization of the Barents Sea after Zinchenko (2000). I–III prov- inces, 1–10 areas, 1–68 local geomorphological elements of less scale. I Outer shelf province, areas: 1 West Barents Area of trenches and hollows (items 1–2), 2 Spitsbergen Upland Area (items:
3–8), 3 North Barents-Kara Area of elevations (items: 9–16). II: Inner shelf province, areas: 4 North Barents Plain Area (items: 17–27), 5 Novaya Zemlya Area of linear uplands and trenches (items: 28–40), 6 Central Upland Area (items: 41–43), 7 Central Lowland Area (items: 44–48), 8 South-Western Area mainly of linear uplands and trenches (items: 49–56). III: Shallow-water province, areas: 9 Kanin-Pechora’s Area, South-Eastern Rapid (items: 57–62), 10 Kanin- Pechora’s Plain Area (items: 63–68)
Fig. 4.8 Distribution of macrobenthos in the Barents Sea and adjacent waters (Kiyko et al. 2006).
Communities: 1 Ophiopleura borealis + Hormosina globulifera, 2 Polychaeta + Sipunculoidea (Golfingia sp.), 3 Trochostoma sp., 4 Elliptica elliptica + Astarte crenata, 5 Brisaster fragilis, 6 soft bottom community adjacent to Svalbard, 7 community of Saint Anna trench slopes, 8 Strongylocentrotus sp. + Ophiopholis aculeata, 9 shoal community of sessile filter-feeders adja- cent to Svalbard, 10 shoal community of sessile filter-feeders on Lithothamnion sp., 11 shoal com- munity adjacent to western coast of Novaya Zemlya and Vise Island, 12 bivalve mollusc Tridonta borealis, 13 bivalve molluscs Ciliatocardium ciliatum + Macoma calcarea + Serripes groenlandi- cus, 14 bivalvie molluscs of Ushakov Plateau, 15 bivalve mollusc Macoma fusca; 16–19 regions of accumulation of pollutants: 16 chlorineorganics, 17 Fe and Mg, 18 polymetallics (Zn, Sn, Cu, Ni), 19 all pollutants by ground feeders
by Balanus balanus, Tridonta borealis, Hydroidea var., Nephthys sp. On soft grounds, Spiochaetopterus typicus, Nephthys sp., Lumbrinereis fragilis prevail.
7. Ecoregion of the Franz Josef Land Archipelago in Fig. 4.6 occupies the North Barents-Kara tectonic and geomorphological areas in Fig. 4.7 and is washed by the Arctic waters. Despite of its northern location, the coastal zone is character- ized by both high biodiversity and productivity. The group of inhabitants includes acrophytobenthos, and sessile and vagile sestonophagous-filtrators. Among ground feeders are the communities of polychaeta and sipunculida, as well as the community of holothurian. The slope community of the Saint Anna trench is formed by Ascidiacea var., Nephasoma minuta, Thenea muricata.